Facebook and other tech companies in Silicon Valley are facing increasing pressure from its shuttle drivers to improve working conditions, amid concern about growing inequality in the area.

Loop Transportation drivers, who transfer Facebook employees to and from the company’s Menlo Park, California campus, have reached an agreement with the contractor that, among other benefits, will increase their average pay to US$24.50 an hour from the current $18 an hour, International Brotherhood of Teamsters said Sunday.

The agreement will have to first be submitted to Facebook for approval as the paying client. The company could not be immediately reached for comment.

“These are life changing improvements for these drivers that will allow them to live a more sustainable life, support their families, have decent health care and plan for the future,” said Rome Aloise, international vice president and secretary-treasurer of Local 853, in a statement about the new agreement.

The organization is now aiming to unionize the drivers of Compass International, which has service agreements with tech companies like Apple, Yahoo, eBay, and Zynga. The drivers for these companies are to vote on representation by the Teamsters later this week.

The use of underpaid contract staff by Silicon Valley companies for functions such as janitors, cooks, drivers and security guards has been criticized previously.